Putting a dent in bruising

Quality control checker Mariana Ixchel Cornelio samples apples from the third or fourth layer in the bin to look for bruising.

Bruising, a major cause of cullage in apples, can be reduced dramatically just by changing the way the fruit is checked.

That’s the theory of Kay Mitsuhashi, a horticulturist with Stemilt Ag Services in Wenatchee, Washington, who believes that the key is to employ checkers who are unrelated to the picking crew.

Two years ago, Mitsuhashi launched a project to help Stemilt orchardists and orchard managers reduce bruising during harvest. They had seen up to 60 percent bruised apples in a bin.

Bruising can be caused by finger pressure, such as when pickers reach up to pick fruit and pull it rather than climb further up the ladder to pick it. Apples can also be bruised if they’re dropped from a height into the picking bag.

Worker training, such as instructional videos, can help reduce –bruising, but Mitsuhashi’s focus is on how fruit is checked for quality.

Stemilt now has teams of specially-hired quality control people who go from orchard to orchard just checking fruit for bruises, punctures, and stemless fruit. Last year, the quality control team members were hired in Wenatchee. This year, most of the 20 quality control employees are agriculture students at the Universidad Autónoma de Chapingo in Durango, Mexico. They are working for Stemilt for three to four months on work and travel visas and will return to their studies in Mexico after harvest.

All varieties

Last season, the program focused only on the bruise-susceptible varieties Golden Delicious, Granny Smith, and Cripps Pink. This year, it was expanded to all varieties, beginning with Gala, which is not considered prone to bruising. Though the bruises might not be obvious externally, Mitsuhashi said that by the time the consumer eats the fruit, there can be unappealing brown corky spots under the skin. She’s seen bruising in Gala as high as 20 to 30 percent.

The apples are inspected three times—in the bin immediately after picking, at the loading dock, and at the warehouse. A sample of 20 apples per bin is examined each time from different parts of the bin, and the results and pickers’ names are recorded. Full results are e-mailed daily to the orchard manager.

It’s important to check bruising in the orchard because when pickers know they’re being monitored, they’re more careful not to bruise the fruit, Mitsuhashi said. Just checking the fruit out of sight of the pickers is far less effective.

"We think it’s psychological," she said. "They think, ‘They’re checking me. I have to do better.’"

It’s important that the checker is not part of the crew or related to any of the pickers, she said. A checker will never admit that a brother or sister is bruising apples, so the results may be biased.

In the orchard, the quality control team members look for flat spots on the apples because bruises don’t turn brown until about 30 minutes later. They score only bruising caused by pickers. Bruising can also be caused by machinery in the orchard or if bins of fruit are handled too roughly by forklift drivers or transported over bumpy roads. By monitoring the fruit all the way to the warehouse and packing line, the different sources of bruising can be identified.

Paul Carter, a field staff manager for Stemilt in southern Washington, said he likes the fact that the quality control team is not connected to the orchard and provides up-to-date, consistent statistical information that he can use to measure how things are going. On large ranches, where big picking crews are being moved around, it’s difficult to have close oversight.

"It’s allowed me to identify problems and reduce bruising," he said. "You don’t want to be out there bothering the people who are doing a good job. You want to have information to direct you to the person causing the problem."

The monitoring has also draw attention to bruising caused by hauling the fruit over bumpy roads, he said. In one case, the amount of bruising decreased after the county leveled the road at his request.

Geraldine Warner was the editor of Good Fruit Grower from 1992-2015. During her tenure, she planned and prepared editorial content, wrote for the magazine, and managed the editorial team.
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